The present invention is directed to a visual indicating paste composition utilized to detect the presence. and particularly the level, of aqueous solutions when admixed with hydrocarbons such as gasoline, oil or other fuel and petroleum fractions. More particularly, the invention is concerned with a visual indicating paste composition which is capable of undergoing a change in color upon contact with aqueous solutions which may be present in minor amounts. generally as a separate phase. in hydrocarbon storage tanks, delivery vehicles, distribution systems, and any other systems for the same purpose. The composition of the invention is particularly adapted for use in determining the water level in the bottom of gasoline storage and transportation tanks to determine the amount of free water resting in a tank that is partially filled with hydrocarbon, and when the water contains oxygenated blending components with gasoline, such as alcohol and ethers. Also the composition of the invention is particularly adopted for use in determining the water level in the bottom of turbine fuel storage and transportation tanks to determine the amount of water resting in the tank partially filled with hydrocarbon. In addition, the paste is particularly useful when the water contains Fuel System Icing Inhibitor (FSII) mixed with Turbine Aviation Fuel, such as Ethylene Glycol Monomethyl Ether (EGME and Diethylene Glycol Monomethyl Ether (DiEGME).
Accordingly, an object of the present invention is to provide a visual indicating paste composition which will, upon contact with aqueous solutions. produce a clear detectable color change.
Another object of the invention is to provide a visual indicating paste for producing a sharp and distinct color change upon contact with aqueous solutions without bleeding, and which reacts rapidly with water admixed with hydrocarbon.
Still another object of the invention is to provide a visual indicating paste with low solubility in aqueous solutions and hydrocarbons. In addition, the paste will have a long shelf life, low hygroscopicity and good adhesion to the substrate to which it is applied during use.
Still another object is to provide a visual indicating composition which is useful for locating the water level of aqueous solutions containing oxygenated blending components in the bottom of tanks and delivery systems containing hydrocarbons such as gasoline, and particularly for indicating sharp and distinct color changes without bleeding or running off the probe to which the paste will be applied.
Still another object is to provide a visual indicating composition paste for producing a sharp color change upon contact with an aqueous solution containing anti-icing additive, which is often mixed with Turbine Fuel Oil. These and other objects, features and advantages of the invention will be apparent from the specification.